Sensors for measuring various types of signals, including physiological signals, often illuminate an individual's tissue with light from a light source and then measure the light that is reflected back onto a detector. For example, photoplethysmographic (PPG) sensors may consist of infrared or green light-emitting diodes (LEDs) and photodetectors for measuring heart rate, oxygen saturation (SpO2), etc. However, the interaction of light with biological tissue such as skin and/or the structure of the sensor itself can be quite complex and typically involves scattering. In other words, not all of the emitted light is reflected toward the photodetector, but is scattered in other non-useful directions after exiting the skin. Metallic surfaces can be used to reflect and/or redirect light to improve sensor performance, but the addition of metallic surfaces can also interfere with electromagnetic and capacitive signal detection. Accordingly, electronic devices having means and methods for collecting and redirecting reflected and/or scattered light may beneficial.